Linear motor with superconducting cable excitation

Abstract

The present invention belongs to the field of superconducting application technology, and provides a linear motor excited by a superconducting cable. The motor includes a rotor and a stator, an air gap is provided between the rotor and the stator, and the rotor moves linearly along the stator. The rotor includes a mover core and an armature winding, a groove is provided in the mover core, and the armature winding is fitted into the groove in the mover core. The stator includes a stator core and a superconducting excitation cable, the superconducting excitation cable is arranged in parallel inside the stator core, the superconducting excitation cable includes a positive cable and a negative cable, and currents flow in opposite directions in the two cables. When current is supplied to the superconducting cable, a magnetic field is generated in the stator core, and the magnetic field is uniformly distributed along the magnetic circuit of the stator core, forming magnetic poles in which N poles and S poles are arranged alternately in the stator core. When three-phase AC current is supplied to the armature winding, a magnetic field is generated that causes linear motion within the air gap. This magnetic field and the stator poles generate a force that drives the rotor in linear motion along the stator, thereby achieving electromechanical energy conversion.

Description

[Technical field]

[0001] The present invention relates to the field of superconducting application technology, and in particular to a linear motor excited by a superconducting cable. [Background technology]

[0002] With the development of railway transportation, magnetic levitation, electromagnetic propulsion and other technologies in China, the demand for high-thrust, high-efficiency linear motors is increasing in the industry. The application of non-resistance, high-current superconducting materials to the field of linear motors can greatly improve the output density and maximum thrust of linear motors while reducing motor losses, making it a promising and important application.

[0003] However, superconducting materials are expensive, their applications are limited by factors such as temperature, magnetic field, and stress, and the structure of a superconducting linear motor is very complicated, and the design of the excitation coil inside the superconducting coil and its low-temperature system is complicated, so the application of the linear motor is difficult, and there are problems of low reliability and high cost. Conventionally, linear motors using superconducting blocks, superconducting linear synchronous motors, and transverse flux type superconducting motors have been proposed as superconducting linear motors. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to provide a superconducting linear motor with superconducting cable excitation, which solves the design problems of the excitation coil and low-temperature system in a superconducting linear motor, has a simple structure and high reliability, greatly reduces the difficulty and cost of motor design, and combines linear motors with superconducting DC transmission technology to further reduce future railway transportation and DC transmission costs. [Means for solving the problem]

[0005] The present invention proposes the following technical solutions:

[0006] A linear motor excited by a superconducting DC cable is provided, the linear motor excited by a superconducting DC cable includes a linear motor rotor and a linear motor stator, the linear motor rotor and the linear motor stator are arranged in parallel with each other and an air gap is provided between them, and the linear motor rotor can perform linear motion in both directions along the linear motor stator.

[0007] Preferably, the linear motor rotor is composed of a mover core and an armature winding. The mover core is provided with grooves on the linear motor stator side, and the armature winding is a three-phase winding that is evenly arranged in the grooves of the mover core. When three-phase AC is supplied to the armature winding, a magnetic field for linear motion can be generated in the air gap.

[0008] Preferably, the linear motor stator is composed of a stator core and two superconducting DC cables arranged in parallel. The superconducting DC cables include a positive transmission cable and a negative transmission cable, and the positive transmission cable and the negative transmission cable are arranged in parallel along the direction of the core. The superconducting DC cable includes a current-carrying superconductor and a dewar, and the dewar is filled with a low-temperature cooling medium. The dewar serves as a heat insulator and a shield against an AC magnetic field. The stator core is made of a high-permeability material and is divided into three parts according to function: a back plate, a T-shaped core, and a C-shaped core. The T-shaped iron cores and C-shaped iron cores are arranged alternately with a gap in between, and the back plate is located under the T-shaped iron cores and C-shaped iron cores, and has two parallel grooves on the upper surface, which are used to fix the superconducting excitation cable, and when current is supplied to the superconducting cable, the back plate plays a role in conducting magnetism, and the magnetic field forms a north pole magnetic field and a south pole magnetic field in the T-shaped iron cores and C-shaped iron cores, respectively, forming the north pole and south pole of the motor excitation system. The configuration of the north pole and south pole is determined by the direction of the current flowing in the superconducting excitation cable.

[0009] Preferably, when a DC current is passed through the superconducting linear cable in the reverse direction, a magnetic field is generated in the stator core, and N and S magnetic poles are formed in the C-shaped core and the T-shaped core, the N and S magnetic poles are arranged alternately, and the armature winding 11 of the mover interacts with the linear motion magnetic field formed in the air gap to press the linear motor rotor in a linear motion, thereby realizing electromechanical energy conversion. Effect of the Invention

[0010] Compared with the prior art, the present invention has the following advantageous effects:

[0011] (1) The linear motor excitation system has a simple structure, is reliable, and economical. It can be applied to long-distance, large-capacity linear motor driving areas.

[0012] (2) The comprehensive use of the cryogenic cooling system of the superconducting DC cable can solve the design problems of complex structures such as the cryogenic system of the superconducting linear motor.

[0013] (3) In the future, this technology can be applied to superconducting DC power transmission projects and rail transport that uses linear motor drive, thereby enabling significant savings in electricity, construction land, and initial investment for transport. [Brief description of the drawings]

[0014] [Figure 1] 1 is a conceptual structural diagram of a linear motor excited by a superconducting cable provided according to an embodiment of the present invention; [Diagram 2] FIG. 2 illustrates a magnetic field line distribution provided by an embodiment of the present invention. [Diagram 3] 4 is a magnetic field simulation result of a linear motor provided by an embodiment of the present invention. [Explanation of symbols]

[0015] 1: linear motor rotor (linear motor rotor); 2: linear motor stator (linear motor stator); 11: armature winding; 12: mover core; 21: negative superconducting DC cable; 22: positive superconducting DC cable; 23: stator core; 221: dewar; 222: current-carrying superconductor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] In order to provide a better understanding of the present invention, the present invention will be described in detail below with reference to the drawings and embodiments, which are provided for the purpose of illustrating the present invention and are not intended to limit the scope of the present invention.

[0017] As shown in FIG. 1, the linear motor excited by a superconducting cable of the present invention includes a linear motor rotor 1 and a linear motor stator 2 .

[0018] In this embodiment, the linear motor rotor 1 and the linear motor stator 2 are arranged in parallel with each other, with an air gap (gap) between them. The linear motor rotor 1 can perform bidirectional linear motion along the linear motor stator 2. The linear motor rotor 1 is composed of a mover core 12 and an armature winding 11. The mover core 12 is provided with a groove on the side of the linear motor stator 2, and the armature winding 11 is a three-phase winding that is evenly arranged within the groove of the mover core 12. When a three-phase AC current is supplied to the armature winding 11, a magnetic field for linear motion can be generated within the air gap.

[0019] The linear motor stator 2 is composed of a stator core 23 and two superconducting DC cables arranged in parallel. The superconducting DC cables include a positive power transmission cable 22 and a negative power transmission cable 21. The positive power transmission cable 22 and the negative power transmission cable 21 are arranged side by side along the direction of the stator core 23. The superconducting DC cable includes a current-carrying superconductor 222, a Dewar 221, and a low-temperature cooling medium filled in the Dewar. The Dewar 221 serves as a heat insulator and a shield against an AC magnetic field. The stator core 23 is made of a high magnetic permeability material and is divided into three parts according to function: a back plate, a T-shaped iron core, and a C-shaped iron core. The back plate serves to fix the superconducting excitation cable and to conduct magnetism. The T-shaped iron core and the C-shaped iron core form magnetic circuits of a north pole magnetic field and a south pole magnetic field, respectively, and form the north pole and south pole of the motor. The configuration of the N and S poles is determined by the direction of the current flow in the superconducting excitation cable. The distribution of magnetic field lines and the magnetic poles of the N and S poles of the linear motor formed are shown in Figure 2. Figure 3 shows the magnetic field distribution formed by a 3D magnetic field simulation.

[0020] When a DC current is passed in the reverse direction through the superconducting linear cable, a magnetic field is generated in the stator core, and N and S magnetic poles are formed in the C-shaped and T-shaped cores. The N and S magnetic poles are arranged alternately, and the armature winding 11 of the mover interacts with the linear motion magnetic field formed in the air gap to press the linear motor rotor in a linear motion, thereby achieving electromechanical energy conversion.

[0021] Although the basic principle, main features and advantages of the present invention have been described above, those skilled in the art will understand that the present invention is not limited to the above-mentioned embodiments. In addition, the above-mentioned embodiments and detailed description of the invention are merely illustrative of the principles of the present invention, and any modifications and improvements can be made without departing from the technical spirit and scope of the present invention, and all such modifications and improvements are included in the scope of the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A linear motor rotor and a linear motor stator are provided. The linear motor rotor and the linear motor stator are arranged in parallel, and an air gap is provided between the linear motor rotor and the linear motor stator; The linear motor rotor is composed of a mover core and an armature winding, the mover core is provided with a groove on the linear motor stator side, and the armature winding is provided to be fitted into the groove, A linear motor excited by a superconducting cable, wherein the linear motor stator comprises a stator core and a superconducting excitation cable.

2. The stator core is divided into three parts: a back plate, a T-shaped core, and a C-shaped core. the superconducting excitation cable includes a positive cable and a negative cable, and currents flowing through the positive cable and the negative cable are direct currents flowing in opposite directions to each other; 2. The linear motor excited by a superconducting cable according to claim 1, wherein said positive and negative superconducting cables are arranged in parallel and pass through the inside of said stator core.

3. 3. The linear motor excited by a superconducting cable according to claim 2, wherein the armature winding is a three-phase winding that is evenly arranged in the groove of the mover core, and a three-phase alternating current is supplied to the armature winding to generate a magnetic field for linear motion.

4. 4. A linear motor excited by a superconducting cable according to claim 3, characterized in that the superconducting DC cable comprises a current-carrying superconductor and a Dewar, the Dewar is filled with a low-temperature cooling medium for cooling the superconductor, and the surface is covered with a shielding material which serves as heat insulation and a shield against an AC magnetic field.

5. 5. The linear motor with superconducting cable excitation according to claim 4, wherein the stator core is made of a material with high magnetic permeability and is divided into three parts, namely, a back plate, a T-shaped core, and a C-shaped core, the T-shaped core and the C-shaped core are arranged alternately with each other, and there is a gap between the T-shaped core and the C-shaped core, the back plate is located under the T-shaped core and the C-shaped core, and has two grooves arranged in parallel on the upper surface, the grooves are used to fix the superconducting excitation cable, and when a current is supplied to the superconducting cable, the back plate plays a role of conducting magnetism, and the magnetic field forms a north pole magnetic field and a south pole magnetic field in the T-shaped core and the C-shaped core, respectively, thereby forming the north pole and the south pole of the motor excitation system.

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